Čerenkov radiation particle counters of a number of types are in satisfactory use in this laboratory for the counting of high energy mesons, electrons, and protons. The problems associated with Čerenkov counting and some of the uses are discussed together with the design and performance of several types of counters. The uses include high energy electron counting with the exclusion of neutrons and protons, measurement of the velocity of mesons, and the detection of high energy neutrons in the presence of lower energy neutrons by the Čerenkov threshold counting of recoil protons.

• Received 25 January 1952

DOI:https://doi.org/10.1103/PhysRev.86.685